Question: What medicine is essential for the treatment of mental disorders?
Paraphrase: What prescription is fundamental for the treatment of mental issue?
SPARQL (Wikidata):  select distinct ?obj where { wd:Q12135 wdt:P2176 ?obj . ?obj wdt:P31 wd:Q35456 } 
Answer: clozapine, haloperidol, lamotrigine, risperidone, fluoxetine